Hi Michelle,
I returned to work in May (SAH in Oct 09) , slowly building up my hours as I feel stronger. I couldn't return to my "original" job as my brain was just not up to it. I'm currently doing an administration role, which is new to me. I initially had bad headaches and moments of sheer frustration but it got better. I have learned new things, I know not as quickly as I would have before, but I have done it! I am hoping to return to my "old" job but i may not be up to it. I do agree with what Liz wrote, if you can or have access to, contact a union. Unison have helped me a lot, so it may be worth you seeing if you can get the same help.
Don't forget, your doing brilliantly just being back at work !!!!